Electro-lift



April 2, 1963 s. GOLDFADER 3,083,948

ELECTRO-LIFT 2 Sheets-Sheet 1 Filed Jan. 15, 1962 IN VEN TOR.

50/ Goldfader April 2, 1963 s. GOLDFADER ELECTRO-LIFT 2 Sheets-Sheet 2Filed Jan. 15. 1962 INVENTOR.

Sol Goldfader United States Patent 3,083,948 ELECTRO-LIFT Sol Goldfader,8116 Halifax Drive, Clayton, Mo. Filed Jan. 15, 1962, Ser. No. 166,344 2Claims. (01.254 1 This invention relates generally to lifting devices,and more specifically to an electrically operated portable hoist ofnovel construction.

It is a primary object of this invention to provide a portable hoistwhich may be raised and lowered in response -to an electrically operatedthread drive which enables precise control of the hoist in bothdirections.

It is a further object of this invention to provide a screw operatedportable hoist which is combined with limit switches for preventingextension or retraction beyond safe limits.

It is a still further object of this invention to provide a portablehoist of the above class which can be used by electrical contractors forhoisting and holding fluorescent fixtures and similar electricalequipment for mounting in the ceiling. It is also adaptable for use inpositioning plasterboard sheets, air conditioning ducts, pipes,sprinkler systems, and all types of elevated structure which is to besupported from the ceiling of the building.

A full understanding of the details of the invention, together withfurther advantages, will become apparent by reference to the followingdetailed description of a preferred embodiment thereof, taken inconjunction with the attached drawings wherein:

FIG. 1 is a perspective View of the portable hoist in the collapsedcondition.

FIG. 2 is a cross sectional side elevation taken along the line 2-2 ofFIG. 1.

FIG. 3 is a fragmentary side elevation taken along the line 33 of FIG.2.

FIG. 4 is a cross sectional plan view taken along the line 4-4 of FIG.3.

FIG. 5 is a cross sectional plan view taken along the line 5-5 of FIG.2.

FIG. 6 is a fragmentary underside view and taken at 66 in FIG. 2.

FIG. 7 is a schematic wiring diagram of the electrical circuit used inoperating the hoist.

Similar reference characters indicate corresponding parts throughout theseveral views in the drawings.

Referring now to the drawings in detail, the numeral 10 represents adome shaped pedestal which is circular in shape and is supported aboutits periphery by four castor wheels 11. A tubular standard 12 projectsupwardly from the centre of the pedestal and is sealed thereto so as tocommunicate inwardly of the pedestal. A fixed bronze bearing 13is'mounted in the lowermost end of the standard and receives the lowerend 14 of a threaded shaft 15 therethrough. The shaft 15 is threadedalong its length as indicated at 16, the said threads terminating at 17at which point a bushing .18 is firmly secured about the shaft. Anintermediate bushing 19 is disposed between the bearing 13 and bushing18 so as to provide a thrust bearing on which the threaded shaft mayrotate on a vertical axis. The lower end 14 of the shaft extends throughthe bearing and terminates within the pedestal with a large belt pulley20. An electric motor 21 is mounted on a platform 22 formed on the outerside of the pedestal such that the motor shaft 23 projects beneath thepedestal and terminates with a drive pulley 24 disposed in a horizontalplane with the pulley 29 for cooperation therewith by means of a belt25.

A threaded boss 26 is slideably received within the standard 12 andengages on the threaded shaft 15 for axial movement therealong inresponse to rotation of Patented Apr. 2, 1963 the shaft by the motor 23. The standard is provided with a slot 27 which extends axially thereofalong the greater part of its length for the purpose of receiving a stoplug 28 therethrough, the stop lug being mounted radially into'the sideof the threaded boss 26. The stop lug prevents rotation of the boss soas to restrict movement of the same longitudinally within the tubularstandard. A tubular extension sleeve 29 is slideably received within thestandard 12. and is secured at its lower end to a protruding portion 30of the boss. The extension sleeve will .thus move longitudinally withrespect to the standard in response to movement of the boss 26.

A telescopic tubular extension 31 protrudes from the upper end of theextension sleeve 29 and is provided with a slot 32 extendinglongitudinally of the extension and terminating inwardly ofthe endsthereof. The tubular extension extends and retracts within the sleeve 29simultaneously with the said extension sleeve. This is accomplished bymounting a small pulley 33 on the coupling 34 which forms the uppermostend of the extension sleeve 29. A strap or wire 35 extends over thepulley and inwardly through the slot 32 terminating within the extensionat its lowermost end 36. The other end of the wire 35 extends downwardlyon the outer side of the extension 31 and is secured to the coupling 37which forms the uppermost end of the tubular standard 12. It will thusbe seen that the extension of the sleeve 29 outwardly of the standardwill simultaneously cause the tubular extension 31 to extend outwardlyof the extension sleeve 29.

The upper end of the telescopic extension 31 terminates with a smallplatform 38 having upstanding sides 39 for the purpose of mountingspecialized adaptors such as 40 shaped to suit the purpose for which thehoist is being used.

The upward extension of the tubular sleeve 29 is limited by a limitswitch 41 which is secured to the upper end of the standard with adownwardly protruding sensing button 42 positioned for engagement by astop arm 43 secured to the protruding stop lug 28.

The stop arm 43 extends downwardly below the stop lug 23 with an arm 44which terminates with a normally protruding roller 45. The roller isadapted to engage with a limit switch 46 which is housed in a casing 47mounted on the pedestal 10. The design of the limit switch is a matterof choice .and both switches may be identical and constructed in aconventional manner.

The hoist may be stabilized when necessary by three telescopic legs 4-8which are bifurcated at 49 at their upper ends for pivotal attachment tothe tubular standard intermediate the length thereof. The legs 48 havetelescopic extension arms 50 which may be locked at a desired extensionby means of wing nuts 51 disposed at the lower end of the legs. Outwardpivotal movement of the legs is restricted by a safety chain 52 whichextends around the legs as indicated in FIG. 1, of the drawing. The legsmay be folded and collapsed adjacent the tubular standard or may beextended in a form of a tripod to stabilize the standard when necessary.

A control switch 53 is provided with spring operated forward and reversebuttons 54 and 55 for controlling the motor when raising or lowering thehoist. It is intended that the switch may be located remotely from thelift if so desired, so as to enable operation from a ladder or otherrelatively remote position.

it will be appreciated that some modifications may be made to theprecise configuration, Without departing from the scope or spirit of theinvention, as defined by the following claims.

I claim:

1. A portable electrically operated hoist comprising, a pedestal, castorwheels mounted on the underside of the pedestal for engagement with theground, an electric motor mounted on the pedestal and having a shaftextending vertically therethrough, a tubular standard secured to projectvertically from the centre of the pedestal, a threaded shaft mountedconcentrically within the standard and protruding through the pedestal,drive means connecting the motor shaft and the protruding portion of thethreaded shaft, a threaded boss slideably mounted within the standardand engaging over the threaded shaft, means preventing rotation of theboss within the standard, a tubular extension sleeve slideably mountedwithin the standard and terminating at its lower end in engagement withthe boss for movement therewith, a telescopic 20 tubular extensionslideably mounted in the extension sleeve, an adaptor removably mountedto the upper end of the telescopic extension, and limit meanscontrolling the degree of extension and retraction of the extensionsleeve with respect to the standard, a slot formed longitudinally of thestandard, a stop lug secured to the boss and protruding through the slotto prevent rotation of the boss, said lug cooperating with the limitmeans to arrest movement of the extension sleeve relative to thestandard.

2. A portable electrically operated hoist according to claim 1, whereinthree telescopic legs are pivotally mounted to the side of the standardfor selective extension in the form of a tripod to engage with theground and provide increased rigidity for the hoist.

References Cited in the file of this patent UNITED STATESPATENTS1,694,243 Wilford Dec. 4, 1928 1,708,761 Horhath Apr. 9, 1929 2,792,913Capgras May 21, 1957 2,969,220 Spencer Jan. 24, 1961

1. A PORTABLE ELECTRICALLY OPERATED HOIST COMPRISING, A PEDESTAL, CASTORWHEELS MOUNTED ON THE UNDERSIDE OF THE PEDESTAL FOR ENGAGEMENT WITH THEGROUND, AN ELECTRIC MOTOR MOUNTED ON THE PEDESTAL AND HAVING A SHAFTEXTENDING VERTICALLY THERETHROUGH, A TUBULAR STANDARD SECURED TO PROJECTVERTICALLY FROM THE CENTRE OF THE PEDESTAL, A THREADED SHAFT MOUNTEDCONCENTRICALLY WITHIN THE STANDARD AND PROTRUDING THROUGH THE PEDESTAL,DRIVE MEANS CONNECTING THE MOTOR SHAFT AND THE PROTRUDING PORTION OF THETHREADED SHAFT, A THREADED BOSS SLIDEABLY MOUNTED WITHIN THE STANDARDAND ENGAGING OVER THE THREADED SHAFT, MEANS PREVENTING ROTATION OF THEBOSS WITHIN THE STANDARD, A TUBULAR EXTENSION SLEEVE SLIDABLY MOUNTEDWITHIN THE STANDARD AND TERMINATING AT ITS LOWER END IN ENGAGEMENT WITHTHE BOSS FOR MOVEMENT THEREWITH, A TELESCOPIC TUBULAR EXTENSIONSLIDEABLY MOUNTED IN THE EXTENSION SLEEVE, AN ADAPTOR REMOVABLY MOUNTEDTO THE UPPER END OF THE TELESCOPIC EXTENSION, AND LIMIT MEANSCONTROLLING THE DEGREE OF EXTENSION AND RETRACTION OF THE EXTENSIONSLEEVE WITH RESPECT TO THE STANDARD, A SLOT FORMED LONGITUDINALLY OF THESTANDARD, A STOP LUG SECURED TO THE BOSS AND PROTRUDING THROUGH THE SLOTTO PREVENT ROTATION OF THE BOSS, SAID LUG COOPERATING WITH THE LIMITMEANS TO ARREST MOVEMENT OF THE EXTENSION SLEEVE RELATIVE TO THESTANDARD.